A liquid crystal display panel is a typical example of a display panel. As a kind of liquid crystal display panel manufacturing method, there is a multiple pattern method in which a plurality of liquid crystal display cells are formed on a large substrate, and will be cut into individual liquid crystal display cells in a later step. In a method of manufacturing a liquid crystal display panel having a small or medium size of about 5 inches, processing is first performed to form a laminated substrate including a plurality of liquid crystal display cells. The laminated substrate includes two large glass substrates adhered together by a sealing member. The large laminated substrate is divided into strip-like laminated substrates.
Then, injection of liquid crystal into the strip-like laminated substrate as well as sealing and the like are performed, and the substrate is divided into individual liquid crystal display cells. Then, an optical film is adhered to a main surface of each of the liquid crystal display cells to complete the liquid crystal display panel. The optical film includes a polarizing plate, a phase plate and the like. Adhesion of the optical film is generally performed in such a manner that the optical films are adhered to the surfaces of the individual liquid crystal display panels one by one.
In this manner, however, the optical films must be adhered to the individual liquid crystal display cells one by one, which results in low production efficiency. Even if a dedicated optical film adhering device is used for the adhesion, static electricity restricts an adhesion speed per one optical film, and therefore the adhesion speed of the optical film can be increased only to a limited extent. This results in a problem that high productivity cannot be ensured without employing a large number of optical film adhering devices for the optical film adhesion. Capital investment for the optical film adhesion significantly increases, and this increases the cost of the final product, i.e., the liquid crystal display device.
Japanese Patent Laying-Open No. 2004-4636 has disclosed a manufacturing method in which liquid crystal is supplied to a region inside a sealing member arranged annularly on one of large substrates, or is supplied to a region on the other large substrate corresponding to the inner side of the sealing member, and these substrates are adhered together. The laminated substrate thus formed includes a plurality of liquid crystal display cells. Large optical films are adhered to the whole laminated substrate, and then the laminated substrate is cut into individual liquid crystal display cells. An apparatus for adhering the large optical film to the laminated substrate is disclosed, e.g., in Japanese Patent Laying-Open No. 2003-161935.
FIG. 18 is a schematic plan of a laminated substrate including a plurality of liquid crystal display cells, and FIG. 19 is a schematic cross section thereof The laminated substrate shown in FIGS. 18 and 19 is provided with 280 liquid crystal display cells in 20 rows and 14 columns. A laminated substrate 34 includes two glass substrates opposed and adhered to each other. An optical film 32 is adhered to each of main surfaces of laminated substrate 34. Laminated substrate 34 includes a plurality of liquid crystal display cells 33. Each of liquid crystal display cells 33 has substantially a rectangular form in a plan view, and is arranged regularly with respect to the others. Liquid crystal display cells 33 are spaced from each other. Each optical film 32 covers all liquid crystal display cells 33 formed at laminated substrate 34.
In a step of dividing the laminated substrate provided with the plurality of liquid crystal display cells into individual liquid crystal display cells, belt-like portions are removed from optical film 32 to expose belt-like regions of the glass substrate as shown in FIG. 20. A film-removed portion 39 represents a portion from which optical film 32 is partially removed. Film-removed portion 39 is formed between the liquid crystal display cells formed at laminated substrate 34. Optical films 32 each having a form corresponding to the liquid crystal display cell are formed.
Then, cracks for division are formed at film-removed portion 39 by a wheel cutter used for glass scribe. Finally, laminated substrate 31 is divided along the cracks thus formed into the individual liquid crystal display cells. The individual liquid crystal display cells thus divided are connected to an external drive device or the like, and are arranged in a casing to complete a liquid crystal display device.
As shown in FIG. 19, some kinds of liquid crystal display panels have such a structure that optical films are adhered to opposite sides of the substrate, respectively. For example, in a transparent type of liquid crystal display panel, optical films are adhered to surfaces on opposite sides of the laminated substrate, respectively.
In a dividing device, the optical film are cut and removed from portions of the laminated substrate located around the liquid crystal display cells, then cracks for division are formed at the film-removed portion and the laminated substrate is divided into the individual liquid crystal display cells. In this dividing device, the laminated substrate is fixed to a stage, the optical film is partially removed with a cutter and the cracks for division are formed at the film-removed portion with a wheel cutter. For example, at the laminated substrate shown in FIG. 20, film-removed portion 39 is formed, and the cracks for division are formed at film-removed portion 39.
When processing of removing the optical film and forming the cracks is to be effected on the laminated substrate having the optical films adhered to the opposite surfaces of the substrates, respectively, the laminated substrate is first fixed to the stage of the dividing device.
FIG. 21 is a schematic cross section showing a state where the laminated substrate is fixed to the stage of the dividing device, and FIG. 22 is a schematic plan thereof. Laminated substrate 31 shown in FIGS. 21 and 22 is provided with the liquid crystal display cells of 20 in total number arranged in 4 rows and 5 columns. The dividing device is configured to fix laminated substrate 31 to a stage 43 by suction.
Stage 43 is provided with a plurality of suction holes 8, which are connected to an evacuation device. Stage 43 has a substantially rectangular form in a plan view. Laminated substrate 31 is arranged substantially on a center of stage 43. Stage 43 has suction grooves 9 that are formed at the surface of stage 43 for communication with suction holes 8. Suction grooves 9 have a grid-like from in the plan view. Suction holes 8 are arranged with certain spaced therebetween. Suction grooves 9 are formed at crossing portions of the grid-like grooves 9, respectively.
Patent Document 1: Japanese Patent Laying-Open No. 2004-4636
Patent Document 2: Japanese Patent Laying-Open No. 2003-161935